Renewable-fuse plug



vv. Q. SMITH. RENEWABLE FUSE PS UG.

APPLICATION FILED JUNE l2. i919.

aten'te Jan. E8, H2L

Unirse stares WALTER `0. SMITH, OF NEW BEDFGRB, MASSACHUSETTS, ASSIGNOR TO REE-NU-IT ELECTRIC MANUFACTURTNG CMANY, OE NEW BEDFORD, MASSACHUSETTS.

RENEWABLE-FUSE PLUG.

Application filed June 12, 1919.

T0 all whom t may concern:

Be it known that l, WALTER SMITH, a citizen of the United States, residing at New Bedford, in the county of Bristol and State of Massachusetts, have invented certain new and useful Improvements in Renewable-F use Plugs, of which the following is a specification.

This invention relates to thermal cut outs and more especially to those which are fusible; and the object of the same is to produce a plug of standard size and thread, wherein the fuse itself may be renewed in case it becomes broken or consumed. p

This object is carried out by making the body of the plug hollow and mounting its cap or cover pivotally on the head of the body so that it can be turned aside to gain access to the fuse chamber, and also by providing detachable means forconnecting the opposite ends of a new fuse with the proper parts of the plug so that when the latter is put back in place the circuit is reestablished.

Details of the preferred manner of carrying out this general idea are set forth in the following specification and claims, and shown in the accompanying drawings wherein:

Figure 1 is a vertical section through the plug complete.

Fig. 2 is a plan view of the plug with its top plate or cover removed, and F ig. 3 is a bottom plan view of the cover.

Fig. 4 is a perspective detail of the wedge, and Fig. 5 a similar detail of a modified form of wedge.

The body 1 of the plug, which is generally of porcelain, is about the size and `contour now in general use, is externally threaded as at 2, is reduced and tapered into what might be called a nose 3 at its lower or frontl end, is enlarged above its threads into what might be called a head l at its upper or rear end, and is hollow, being provided with an eccentric chamber 5 opening out the upper end las seen in Fig. 2 and having a passage 6 leading down through and opening out the lower end of the nose, the lower portion of the passage being enlarged as indicated at 7. Around said body is secured the usual metal sleeve 8 whose lower end is turned inward into a flange 9 above the nose, and the Speccation of Letters Patent.

Patented Jan. 18, 1921.

Serial No. 303,618.

threads on this sleeve correspond with those on the body and will fit the female threads in the usual fuse block.

The covei` 10, which is also by preference of porcelain, is made in the shape of a disk whose circumference corresponds with thatJ of the head et, and this cover might be provided with a mica covered opening through which the fuse within the chamber could be seen although as such feature forms no part of the present invention it is not illustrated. A bolt 11 passes through the flange 9 of the sleeve and upward throughout the body 1 where the latter is thickest by reason of the eccentric disposition of the chamber 5, and the head 12 of the bolt will be caused to make good electric contact with the flange by any appropriate means, and possibly by the use of a drop of solder as is common. The threaded upper end of this bolt passes centrally through a recess 13 formed in the under side of the cover, above which it is extended completely through the cover, and its upper extremity may receive a cap nut 14C. l/Vithin said recess are disposed two washers 15 and a milled nut 16, all mounted on the bolt. The fuse 17 has its upper end placed between the two washers, and good electrical contact is made by tightening the milled nut before the cover and cap nut have been applied. They are then put on in a manner which will be clear, and in order to hold the cover accurately over the head, the cover has on its under side a lip 18 which fits within the upper end of the chamber. rllhe recess 13 must overlap the mouth of the chamber slightly so that the fuse may lead from the former into the latter as shown in Fig. 1.

The lower end of the fuse is carried down through the passage 6 and transversely across one side of the extremity of the nose 3, and for holding the fuse in place l employ a wedge best seen in Fig. et. This consists of a slightly tapering body 2O shaped to fit the tapering or enlarged portion 7 of the passage, and a head integral with the body and made in the shape of a button 21 which covers the end of the nose when the wedge is in place. It is obvious that this element forms the central terminal of the fuse plug, while the sleeve 8 constitutes the other ter minal as usual. A modified form of wedge is shown in Fig. 5, wherein this member is made of a sheet metal strip bent so that its central portion constitutes a flat head 22, beyond which the strip is folded back upon itself as at 23, and beyond this folded portion in turn the ends of the strip are carried upward and caused to converge slightly in leaves 211C which collectively correspond with the wedge-shaped body 20 shown in F ig. it

This plug finds its usual use which need not be described here. lVhen the fuse 17 becomes broken or burned out and it is desired to replace it, the entire plug is unscrewed from the fuse block and removed, the cap nut 14 is loosened so that the cover can be raised until its lip 18 comes out of engagement with the wall of the chamber 5, and then the cover can be turned aside to inspect the fuse. 1f the latter is found to need replacement, the nut 14 and cover are wholly removed, the milled nut 16 run up on the threads of the bolt until the washers 15 release the upper end of the fuse 17, the nail inserted over the button and the wedge withdrawn so that the lower end of the 'old fuse is released, and this element shaken ont of the plug. A new piece of fuse wire or ribbon is now brought into use and its lower end threaded down through the passage 6 and turned aside as shown, being held teinporarily in place by lightly inserting the wedge. Its body is now led up through the chamber 5 and between the washers 15, and when it is drawn or slipped upward until no extremity 25 appears, the wedge is pushed in tight. Now the body is drawn as taut as necessary, broken off at the far side of the washers, and the milled nut run down to hold the parts together. Finally the cover is applied, its lip 1S engaged with the chamber 5, and the cap nut 14 run onto the screw to hold all parts in position. Now the plug as a whole can be reinserted in the fuse block by screwing it into the appropriate socket therein as is common.

Attention is invited to the fact that there is no part of this plug to be destroyed encepting the fuse itself, and therefore the owner who is provided with a reasonable supply of fuse wire of the proper gage can use the plug over and over again for years, as it requires no instruments and very little instruction for an unskilled person to replenish the fuse wire. Or the dealer might keep a supply of these plugs on hand and sell them to customers who contemplate putting them to widely different uses, adapting the devices to each specific case by supplying the customer with a coil of fuse wire or ribbon of proper gage. Finally, it is of course possible for the user to change the fuse in the plug at any time when it becomes necessary or desirable to do so, as where the load on the circuit has been or will be altered, and such change can be effected by substituting a new piece of fuse and still utilizing the plug itself.

Having thus described the invention, what is claimed as new is:

1. A fuse plug having a chamber eccentric to its body and opening out the rear end thereof, its front end being reduced to a nose and the latter provided with an axial passage communicating with the chamber, a. threaded sleeve fast around and flanged over the front end of the body at the base of the nose, and a bolt extending' through the body with its head engaging said flange and its projecting rear end carrying a nut and washers; combined with a fuse whose rear end is clamped between said washers. whose body leads through the chamber, and whose front end extends into said passage, and a closure for the rear of said chamber removably carried by the bolt.

Q. .la fuse plug havircf a chamber eccentric to its bf dy and opening out the rear end theref, its front end being reduced to a nose and the latter provided with an anal communica with the chamber, a threaded sleeve fa. around and flanged over the front end of the body at the base of the nose, and a bolt e3v ending through the body with its head engaging said flange and its projecting end carrying a. nut and washey combined with a fuse whose refr end is ciamped between said washers. whose body leads through the chamber, and whose fron.,I end is confined within said passage, a cover extending across the rearcnd 'of the body and closingits chamber, the cover having a recess in losing thD nut and washers and said bolt extending across the re fess and through the cover, and a cap nut on the tip of the bolt.

3. .ftfuse plug having a chamber opening out through the rear end thereof, its front end being reduced to a nose and the latter provided with an axial passage communicating with the chamber, a threaded sleeve fast around and danged over the front end of the body at the base of the nose, and a bolt eX- tending through the body with its head engaging said flange and its projecting rear end carrying a nut and washers, combined with a fuse whose rear end is clamped between said washers, whose body leads through the chamber, and whose front end entends into said passage, a cover conforming in contour with and overlying the rear end of the body and ha ring a lip projecting into said chamber near one side of the body and a recess in its under face near the other side of the body inclosing said nut and washers, and means for holding the cover removably in place.

i, A fuse plug including a body, a fuse anchored at one end of the body, a bolt carried by the body and having a pair of disk washers between which the other end portion of the fuse is arranged, and a nut hav ing threaded engagement with said bolt and adapted for tightly clamping said washers in engagement with opposite sides of said fuse.

5. A fuse plug including a body, a fuse detachably connected to one end of the body, a bolt carried by the body, a pair of disk washers mounted on the threaded portion of said bolt, the other end portion of said fuse being extended between said washers, a nut having threaded engagement with said bolt and adapted to tightly clamp said washers in contact with said fuse, a cover mounted on one end of said body and having a recess receiving said washers and the adjacent end of said use, a nut threaded on the outer end portion of said bolt for securing said cover in position, and a depending lip carried by the underside of said cover and engaging said body.

6. In a fuse plug, the combination with a body having a chamber eccentric to its aXis and opening out its rear end and a passage leading from said chamber and opening out the front end of the body, a cover overlying said rear end and having a recess in its inner face communicating at one point with said chamber but mostly closed by the wall of the body where such wall around the chamber is thickest, and a lip on the inner tace of the cover diametrically opposite its recess and adapted to project into the chamber; of a bolt seated in said wall at its thickest point, an annular Contact on the body electrically connected with said bolt, a button having a wedge extending into said opening, a fuse whereof one end is clamped between the wedge and the wall of the open ing, its body passing through said chamber and its opposite end leading into said recess, means within the latter for electrically connecting its other end to said bolt, and means on the bolt for removably fastening the cover in place.

7. In a fuse plug, the combination with a body having a chamber opening out through its rear end and a passage leading from said chamber and opening out through its forward end, a cover overlying said rear end and having a recess communicating at one point with said opening and principally closed by the wall of the body where such wall around said opening is thickened, and a lip on the inner face of the cover diametrically opposite the recess in the same and adapted to project into said chamber, of a bolt seated in said wall at its thickened point, an annular Contact on the body electrically connected with said bolt, a fuse having one end conned within said opening, a nut and washer for connecting said fuse to said bolt, said cover being provided with an opening through which the threaded end of the bolt projects, and a cap nut on the tip of the bolt removably holding the cover in place.

8. A. 'fuse plug including a cylindrical body having its forward end portion reduced and provided with an inwardly tapered opening, a fuse extended through said inwardly tapered portion and having its terminal extended laterally and in contact with the forward end of said reduced portion, a tapered wedge inserted in said inwardly tapered opening and provided with a head in contact with said terminal portion of the fuse, and a contact associated with the other terminal of the fuse.

In testimony whereof I aHiX my signature.

WALTER O. SMITH. [La] 

